Oiling means

ABSTRACT

A pump oiler has a supply maintaining a constant level of oil in a bowl wick take up oil from the bowl and pass the oil through a tube which is connected through sight feed indicators to the bearings of a vacuum pump. An air bleed is provided in the connections and by adjustment of the air bleed a suitable rate of air is caused to flow through the bearings from the bowl and this flow of air entrains oil from the bowl for lubrication of the pump.

United States Patent Boswell 1 Mar.'2l, 1972 OILING MEANS [72] Inventor: Gordon H. Boswell, Pakuranga, NewZea land [73] Assignee: Mason & Porter Limited, Panmure, Auckland, New Zealand 221' Filed: July 9, 1970 211 Appl. No.: 53,379

52 u.s.c| ..184/59,184/64 s11 Int.Cl ..Fl6n 17/06 58 FieldofSearch ..'184/58,59,76,64,102,96

[56] References Cited UNITED STATES PATENTS 2,589,081 3/1952 Hertz ..l84/58X 2,527,422 10/1950 l-lollingshead ..184/64 3,053,343 9/ l 962 Hornbostel 184/96 2,460,81 4 2/1949 ...l84/58 X 2,496,676 2/1950 184/96 X 3,393,770 7/1968 184/58 X Primary Examiner-Manuel A. Antonakas Attorney-Holman & Stern [5 7] ABSTRACT A pump oiler has a supply maintaining a constant level of oil in a bowl wick take up oil from the bowl and pass the oil through a tube which is connected through sight feed indicators to the bearings of a vacuum pump. An air bleed is provided in the connections and by adjustment of the air bleed a suitable rate of air is caused to flow through the bearings from the bowl and this flow of air entrains oil from the bowl for lubrication of the pump.

6 Claims, 4 Drawing Figures l gt ented March 21, 1972 3,650,355

4 Sheets-Sheet 1 FIG. 7.. v 4

IMgNTOR BY w ATTORNEYS Patented March 21, 195 2 4 Sheets-Sheet 2 FIG).

5 INVENTOR flmM a-tm ZTTORNEYS Patented March 21, 1972 3,650,355

I 4 Sheets-Sheet 5 a E 41 FIG. 3.

5 wgmoa ATTORNEYS Patented March 21, 1972 3,650,355

4 Sheets-Sheet 4.

EZ/ f7 49%} V I I I 4 ATTORNEYS OILING MEANS This invention relates to oiling means, and has been devised particularly though not solely for use in oiling the bearing, vanes, and other working parts of what are'commonly called vacuum pumps, that is to say, pumps which create a reduced pressure below atmospheric pressure on one side of the pump. Such pumps will be hereinafter referred to, as is the common practice, as vacuum pumps.

The working parts of vacuum pumps require a small substantially consistent flow of oil and it is very difficult to adjust the oil flow with apparatus as to present in use. Either the oil has to be adjusted, so that if flows readily, when cold and viscous, in which event there is a considerable waste of oil because oil flows much more freely when it is hot and, therefore, thinner, or, alternatively, some risk must be taken that oil will not be provided in sufficient quantities when the pump is cold.

It is, therefore, an object of the present invention to provide oiling means which will obviate or minimize the foregoing disadvantages in a simple yet effective manner, or which will at least provide the public with a useful choice.

Accordingly, the invention consists in an oiling means comprising a bowl, adapted to contain oil, tube means mounted in said bowl, wick means leading upwardly from the oil in said bowl to said tube means in a manner such that oil will be conducted to the tube means by capillary attraction, passage means connecting said tube means to the device to be oiled, for example, a pump, and air flow creating means adapted to cause a flow of air to pass through said tube means in a manner such that the oil collecting on said wick means within said tube means will be conveyed by said flow of air in use to the device being oiled.

One preferred form of the invention will now be described with reference to the accompanying drawings in which,

FIG. 1 is a perspective sketch of an oiling means according to the invention mounted in position on a vacuum pump. Shown in part only,

FIG. 2 is a cross section of the oiling means shown in FIG. 1 on a line through the vertical center of the oiling means, the air flow creating means being omitted,

FIG. 3 is a partly diagrammatic cross section of a vacuum pump showing oilways therein, and having part of the oiling means affixed thereto, and

FIG. 4 is an elevation of an alternative form of oil reservoir.

Referring to the drawings, an oiling means for association with what is commonly called a vacuum pump as above defined, is constructed as follows: i

A bowl 1, is provided, with which is associated a supply means 2. The supply means 2 is shown more clearly in FIG. 2 in which a chamber 3 has mounted on it an inverted bottle or container 4 having, for example, a cap 5 with a flange 6 resting on a ledge 7 on the chamber 3. The cap 5 has an air opening 8 communicating from the ambient air to the interior of the chamber 3. The bottle is supported by a pair of brackets 9 held by studs 10 screwed into the wall 11 of the chamber 3. The cap 5 has a nozzle 12 which reaches to close to the bottom of the chamber 3, and if the bottle 4 is filled or partially filled with oil, and inverted to the position shown in the drawings, the oil will run into the chamber 3 until a certain level is reached. This, of course, is the well known chicken feed principle, that is to say, the oil runs from the inverted bottle only when air can enter the bottle through the level of the oil falling below the end of the nozzle 12. A passageway 13 leads from the bottom of the chamber 3 and terminates in a face 14 which forms a valve seat leading to a further chamber 15 connected by a passageway 16 to the interior of the bowl 1. A valve means, e.g., a diagram 17, is normally maintained in contact with the valve face 14 by a plunger 18 and spring 19, the spring abutting against a washer20, held on a ledge 21 in a stem 22 fixed in the pump casing 24 (FIG. 1).

In place of the diaphragm 17, the plunger 18 may be formed as a piston having the face thereof which contacts the valve seat 14 coated with a flexible sealing material to form a valve member, the vacuum withdrawing the piston in a cylinder formed by the internal walls of the stem 22. A restricted opening 23 leads into the part of the interior of the pump casing which is subjected to the reduced pressure created by operation of the pump. Thus, when the pump is not operating, the diaphragm 17 is pressed against the valve seat 14 by the spring 19 preventing the delivery of oil from the chamber3 to the passageway 16 and thus the bowl 1. When the pump is operating, the diaphragm 17 is pulled off the valve seat 14 bythe vacuum through the restricted opening 23 so that oil will now feed into the bowl 1. In the bowl 1, a pair of tube means 25 are provided which do not communicate with the interior 26 of the bowl otherwise than through an opening 27 in the top thereof. The lower end of each tube connects through a flexible tube 28 to an airflow control means 29 FIG. 1) through a sight bowl 30. In each tube 25 wick means 31 are provided, comprising a loop of stranded cotton or wool or other wick material inserted in the tube 25 by a twisted wire loop 32. The free ends 33 of the wick means 31 are arranged to lie adjacent the bottom of the bowl 1.

The sight feed bowl 30 comprises a transparent member 3312 in the form of an enlargement of the tube 28, into which an extension 34 of the tube 28 protrudes with a space 35 between the end 36 of the tube extension 34 and the wall 37 of the member 33. A passageway 38 communicates with a further passageway 39, the upper end of the passage 39 being connected to atmosphere through a cross passage 40, and the size of the opening of the cross passage 40 to the ambient atmosphere is controllable to form an adjustable air bleed valve by a screw means 41. The lower end of the passage 39 connects to a space 41 in which a bearing 42 of the pump shaft 43 operates. The pump shaft carries a rotor 44 having sliding vanes (not shown) and the pump housing 24 carries end plates 45.

If desired, the bottle 4 may be replaced by a fixed container 46 (FIG. 4) which is preferably transparent to enable the level of oil to be seen, having a filler cap 47, the oil again running into the chamber 3 through a nozzle 48 connected through a passageway 49 to an opening 50 in the bottom of the fixed container 46. The container 46 may be a composite container made up of a cylindrical transparent member 51, and two end caps 52 connected by a stud 53 and acorn nut 54 or it may be, for example, a moulded plastic article, or any other convenient container, which can be made airtight above the n'ozzle 48.

The use of the construction is as follows:

It will be assumed that the pump is at rest, and that the container 4 or 46 is empty. The-operator then puts oil in the container 4 or 46, and in the case of the container 4, inverts it so that the nozzle 12 is within the chamber 3. As a result, oil will flow into the chamber and reach alevel where the open mouth of the nozzle 12 is covered by oil. The same applies in the case of the container shown in FIG. 4. Oil will not flow out of the chamber 3 because the diaphragm 17 is in contact with the valve seat 14. When the pump starts to run, a reduced pressure is communicated through the restricted aperture 23, to the diaphragm 17, pulling it away from the valve seat 14. Oil is admitted to the chamber 15 and, consequently, through the passageway 16 to the bowl 1. This oil is picked up by capillary attraction by the wicks 31 and carried up into the tubes 25. As a result of the pump running, there will also be a pressure differential across the bearings 42, tending to draw air through the opening 40, and the passageway 39 and to the bearings 42 into the pump. Also, air will tend to be drawn through the passageway 38 and the tubes 28 which lead to the tubes 25. The lid 56 of the bowl 1 is arranged so that air may flow around the'edges 57 of the lid into the interior of the bowl 1, so that a flow of air is created through the tubes 25, 28, 38, 39 into the chamber 41 and through the bearings 42 into the interior of the pump. This flow of air entrains oil picked up from the wicks 31 and asa result of which, oil will be carried and the rate of flowof the oil can be observed dripping from the nozzle 36 of the tube 34 into the sight glass 30. This is of particular advantage. The rate of flow of air can be modified by altering the position of the screw means 41, relative to the hole 40. If this hole 40 is wider open, then little air passes through the tubes 25. If, however, the screw 41 completely closes the hole 40, the whole of the air passing through the valves 42 will pass through the tubes 25 from the bowl, so that a greater flow of oil will be created. Having been drawn through the bearings, the oil continues on into the pump, and there lubricates the vanes, the cylindrical wall and other movable parts. Some of the oil tends to collect inside the roter 44 which is hollow, and this passes through cast oil channels to lubricate the vanes as they slide in die rotor. The rest of the oil passes between the ends of the rotor and the end covers of the cylinder, and is spread on the inside of the cylinder by the wiping action of the vanes. Oil consumption is of the order of 1 gallon per 100 to 200 hours running, and it has been found that needle type valve regulators are unreliable at such low flow rates, and can give unexpected shutdowns of oil supply which could be disastrous.

When the pump starts, and a vacuum of about6 inches of mercury is reached, the diaphragm is pulled away from its seat, and oil flows into the bowl until it reaches the same level as the spout on the'bottle cap. Air and oil are drawn through the wick (inside the wick tube), along the oil passages, through the bearings, and on into the internal parts of the pump. The bottle 4 or container 46 maintains a constant oil level in the bowl 1 at all times as long as the diaphragm is pulled away from its seat. (Operating vacuum in the system is usually between and 20 inches of mercury). When the pump is stopped the diaphragm l7 closes off the oil supply to the bowl, but the bowl is still full to operating level. Consequently, after the pump is stopped, the oil in the bowl will still pass into the tubes under the normal capillary action of the wicks, although this will be at a lower rate than the normal operating flow.

The oil passage arrangements are such that the oil can flow downhill all the way into the pump where it accumulates as an initial shot to lubricate the pump the next time it starts, thus carrying it over the short period while the bowl is filling to operating level (this takes 2 or 3 minutes). An additional benefit is derived from the fact that when the pump is cold, the working clearances inside are greater than when it has reached full operating temperature. This increased clearance provides a correspondingly greater than normal suction at the bearings, and a consequently increased air flow through the wicks, thus helping compensate for the greater viscosity of the cold oil. (The oil temperature rises during running as heat is conducted up through the bottle mounting from the pump). Because of the flow of air through the tube, encompassing the wick due to air pressure on the upper end thereof, and the reduced pressure within the tube, we have found somewhat surprisingly, that the control of oil is much more satisfactory, in that a substantially even rate of flow is obtained whether the oil be thick or thin. Needle valve type regulators have been found more susceptible to variations in flow rate with changing oil viscosities (due to temperature fluctuations) than are wick feed type regulators, and, of course are very susceptible to blockage due to dirt, but small amounts of dirt will not cause shut down of flow through a wick feed. Thus, in devising the invention, having established the desirability of using a wick, it was then found necessary to be able to adjust the flow of oil through the wick to a suitable rate. This can be don by altering the vertical distance from the oil level to the top of the wick tube, but this is inconvenient, inaccurate, and tedious. The present invention lies in the method of using an oil wick having a fixed vertical distance from oil level to wick tube top and applying air suction to the wick in sufficient amount to increase the fundamental oil flow rate to the desired degree.

Thus, if the wick gives, say X drops per minute without air flow, this can be increased up to say 3X drops per minute. Obviously, by applying less air suction to the wick, the flow rate will be increased to a lesser degree. For this system to work well, the wick should loosely fill the wick tube, or else the air can bypass it.

The air suction applied to the wick can be controlled in two ways:

l. by placing a metering valve in the passage between the bearing and the wick,

2. by bleeding a controlled amount of air into the passage between the bearing and the wick at some intermediate point.

Both methods have been used, but the second is preferred as it gives a smoother adjustment.

Because of the adjustment means, the rate of flow can be readily adjusted as between one bearing and theother, to give a substantially equal oil supply to each end of the pump, the rates of flow being readily observable. Thus, we have found that a very effective air flow control can be obtained in a simple manner, enabling oiling of the bearings and general lubrication of a pump to be obtained in an automatic manner, which is particularly efficacious and economical.

I claim:

1. An oiling means adapted for use with a vacuum pump as herein defined, said oiling means having a bowl adapted to contain oil, said bowl having air entry means above the surface of the oil therein, oil supply means adapted to maintain a substantially constant level of oil in said bowl, tube means mounted in said bowl and having an inlet and an outlet with the inlet to the tube means above the level of oil in the bowl and the outlet from said tube means leading to the vacuum pump, wick means partially inserted in an upper part of said tube means and having free ends below the oil level in the oil bowl so that oil will be conducted from the bowl to the tube means by capillary attraction, oil delivery means between said tube means and the vacuum pump,and auxiliary controllable air entry means disposed in said delivery means, operation of the control thereof controlling the entry of air which has not passed said wick means so that in turn the flow of air through said tube means which carries with it oil from said wick means is controlled to control the rate of flow of oil to the vacuum pump.

2. Oiling means as claimed in claim 1 further comprising valve means operable on running the vacuum pump to open and permit flow of oil from said supply means to said bowl.

3. Oiling means as claimed in claim 2 wherein said valve means are operable by the creation of a reduced pressure by the vacuum pump.

4. Oiling means as claimed in claim 1 further comprising air flow control means including an adjustable air bleed adapted to bleed atmospheric air into said delivery means thus controlling the air flow passing through said tube means.

5. Oiling means as claimed in claim 1, further comprising sight feed meansprovided in said delivery means, said sight feed means comprising a transparently walled enlargement of said delivery means and an orifice visible through the transparent wall of said enlargement through which oil is in use admitted to such enlargement before passing to the vacuum pump.

6. Oiling means as claimed in claim 1, further comprising air flow creating means including a connection to a chamber outside each rotor shaft bearing of the vacuum pump which is subjected to reduced pressure due to a pressure differential created by the pump across such bearings. 

1. An oiling means adapted for use with a vacuum pump as herein defined, said oiling means having a bowl adapted to contain oil, said bowl having air entry means above the surface of the oil therein, oil supply means adapted to maintain a substantially constant level of oil in said bowl, tube means mounted in said bowl and having an inlet and an outlet with the inlet to the tube means above the level of oil in the bowl and the outlet from said tube means leading to the vacuum pump, wick means partially inserted in an upper part of said tube means and having free ends below the oil level in the oil bowl so that oil will be conducted from the bowl to the tube means by capillary attraction, oil delivery means between said tube means and the vacuum pump, and auxiliary controllable air entry means disposed in said delivery means, operation of the control thereof controlling the entry of air which has not passed said wick means so that in turn the flow of air through said tube means which carries with it oil from said wick means is controlled to control the rate of flow of oil to the vacuum pump.
 2. Oiling Means as claimed in claim 1 further comprising valve means operable on running the vacuum pump to open and permit flow of oil from said supply means to said bowl.
 3. Oiling means as claimed in claim 2 wherein said valve means are operable by the creation of a reduced pressure by the vacuum pump.
 4. Oiling means as claimed in claim 1 further comprising air flow control means including an adjustable air bleed adapted to bleed atmospheric air into said delivery means thus controlling the air flow passing through said tube means.
 5. Oiling means as claimed in claim 1, further comprising sight feed means provided in said delivery means, said sight feed means comprising a transparently walled enlargement of said delivery means and an orifice visible through the transparent wall of said enlargement through which oil is in use admitted to such enlargement before passing to the vacuum pump.
 6. Oiling means as claimed in claim 1, further comprising air flow creating means including a connection to a chamber outside each rotor shaft bearing of the vacuum pump which is subjected to reduced pressure due to a pressure differential created by the pump across such bearings. 